A diagnostic system for an inverter module includes a motor control module configured to determine operating characteristics of the inverter module. The operating characteristics include of at least one of a voltage, a current, and a switching frequency associated with operation of the inverter module. A diagnostic module is configured to receive the operating characteristics of the inverter module, estimate at least one junction temperature of a component of the inverter module based on the operating characteristics, calculate a health indicator of the inverter module based on the estimated junction temperature, and selectively output an alert based on the calculated health indicator.